Referring to FIG. 1, a surgical stapler 2 typically includes a staple holder 4 and an anvil 6. The staple holder 4 and anvil 6 are configured to close together and clamp tissue therebetween. After clamping, the staple holder 4 deploys a plurality of staples into that tissue. A challenge faced by most surgical staplers 2 is beam deflection. When the surgical stapler 2 clamps tissue that is sufficiently thick and/or tough, the distal end of the anvil 6 may not close completely relative to the staple holder 4. Instead, the distal end of the anvil 6 may bend away from the staple holder 4, because more force is required to compress the tissue than to cause the distal end of the anvil 6 to bend. Many attempts have been made to solve this problem. Some surgical staplers 2 utilize an “I-beam” mechanism, where the upper and lower portions of the I-beam each slide in a corresponding channel in the staple holder 4 and anvil 6. However, the I-beam takes up space in the surgical stapler 2, limits cutting and stapling operations to being performed by motion in the distal direction, and adds to the part count. Other surgical staplers 2 have been proposed that utilize exotic, highly-stiff materials to reduce or eliminate beam deflection. Stiffness is the force required to produce a unit deflection of a structure, and is related to the elastic modulus of the material from which the structure is fabricated. Strength is the ability of a structure to resist loads. However, it is a truism of material science that stiff, high-modulus materials are not high-strength materials, with the result that such materials are not practical for fabrication of an anvil 6.
The use of the same reference symbols in different figures indicates similar or identical items.